<?php

namespace GetId3\Module\Tag;

use GetId3\Handler\BaseHandler;
use GetId3\Lib\Helper;
use GetId3\GetId3Core;

/////////////////////////////////////////////////////////////////
/// GetId3() by James Heinrich <info@getid3.org>               //
//  available at http://getid3.sourceforge.net                 //
//            or http://www.getid3.org                         //
/////////////////////////////////////////////////////////////////
// See readme.txt for more details                             //
/////////////////////////////////////////////////////////////////
///                                                            //
// module.tag.lyrics3.php                                      //
// module for analyzing Lyrics3 tags                           //
// dependencies: module.tag.apetag.php (optional)              //
//                                                            ///
/////////////////////////////////////////////////////////////////

/**
 * module for analyzing Lyrics3 tags
 *
 * @author James Heinrich <info@getid3.org>
 *
 * @link http://getid3.sourceforge.net
 * @link http://www.getid3.org
 *
 * @uses GetId3\Module\Tag\Apetag
 */
class Lyrics3 extends BaseHandler
{
    /**
     * @return bool
     */
    public function analyze()
    {
        $info = &$this->getid3->info;

        // http://www.volweb.cz/str/tags.htm

        if (!Helper::intValueSupported($info['filesize'])) {
            $info['warning'][] = 'Unable to check for Lyrics3 because file is larger than '.round(PHP_INT_MAX / 1073741824).'GB';

            return false;
        }

        fseek($this->getid3->fp, (0 - 128 - 9 - 6), SEEK_END);          // end - ID3v1 - "LYRICSEND" - [Lyrics3size]
        $lyrics3_id3v1 = fread($this->getid3->fp, 128 + 9 + 6);
        $lyrics3lsz = substr($lyrics3_id3v1, 0, 6); // Lyrics3size
        $lyrics3end = substr($lyrics3_id3v1, 6, 9); // LYRICSEND or LYRICS200
        $id3v1tag = substr($lyrics3_id3v1, 15, 128); // ID3v1

        if ($lyrics3end == 'LYRICSEND') {
            // Lyrics3v1, ID3v1, no APE

            $lyrics3size = 5100;
            $lyrics3offset = $info['filesize'] - 128 - $lyrics3size;
            $lyrics3version = 1;
        } elseif ($lyrics3end == 'LYRICS200') {
            // Lyrics3v2, ID3v1, no APE

            // LSZ = lyrics + 'LYRICSBEGIN'; add 6-byte size field; add 'LYRICS200'
            $lyrics3size = $lyrics3lsz + 6 + strlen('LYRICS200');
            $lyrics3offset = $info['filesize'] - 128 - $lyrics3size;
            $lyrics3version = 2;
        } elseif (substr(strrev($lyrics3_id3v1), 0, 9) == strrev('LYRICSEND')) {
            // Lyrics3v1, no ID3v1, no APE

            $lyrics3size = 5100;
            $lyrics3offset = $info['filesize'] - $lyrics3size;
            $lyrics3version = 1;
            $lyrics3offset = $info['filesize'] - $lyrics3size;
        } elseif (substr(strrev($lyrics3_id3v1), 0, 9) == strrev('LYRICS200')) {

            // Lyrics3v2, no ID3v1, no APE

            $lyrics3size = strrev(substr(strrev($lyrics3_id3v1), 9, 6)) + 6 + strlen('LYRICS200'); // LSZ = lyrics + 'LYRICSBEGIN'; add 6-byte size field; add 'LYRICS200'
            $lyrics3offset = $info['filesize'] - $lyrics3size;
            $lyrics3version = 2;
        } else {
            if (isset($info['ape']['tag_offset_start']) && ($info['ape']['tag_offset_start'] > 15)) {
                fseek($this->getid3->fp, $info['ape']['tag_offset_start'] - 15, SEEK_SET);
                $lyrics3lsz = fread($this->getid3->fp, 6);
                $lyrics3end = fread($this->getid3->fp, 9);

                if ($lyrics3end == 'LYRICSEND') {
                    // Lyrics3v1, APE, maybe ID3v1

                    $lyrics3size = 5100;
                    $lyrics3offset = $info['ape']['tag_offset_start'] - $lyrics3size;
                    $info['avdataend'] = $lyrics3offset;
                    $lyrics3version = 1;
                    $info['warning'][] = 'APE tag located after Lyrics3, will probably break Lyrics3 compatability';
                } elseif ($lyrics3end == 'LYRICS200') {
                    // Lyrics3v2, APE, maybe ID3v1

                    $lyrics3size = $lyrics3lsz + 6 + strlen('LYRICS200'); // LSZ = lyrics + 'LYRICSBEGIN'; add 6-byte size field; add 'LYRICS200'
                    $lyrics3offset = $info['ape']['tag_offset_start'] - $lyrics3size;
                    $lyrics3version = 2;
                    $info['warning'][] = 'APE tag located after Lyrics3, will probably break Lyrics3 compatability';
                }
            }
        }

        if (isset($lyrics3offset)) {
            $info['avdataend'] = $lyrics3offset;
            $this->getLyrics3Data($lyrics3offset, $lyrics3version, $lyrics3size);

            if (!isset($info['ape'])) {
                $GETID3_ERRORARRAY = &$info['warning'];

                if (class_exists('GetId3\\Module\\Tag\\Apetag')) {
                    $getid3_temp = new GetId3Core();
                    $getid3_temp->openfile($this->getid3->filename);
                    $getid3_apetag = new Apetag($getid3_temp);
                    $getid3_apetag->overrideendoffset = $info['lyrics3']['tag_offset_start'];
                    $getid3_apetag->analyze();
                    if (!empty($getid3_temp->info['ape'])) {
                        $info['ape'] = $getid3_temp->info['ape'];
                    }
                    if (!empty($getid3_temp->info['replay_gain'])) {
                        $info['replay_gain'] = $getid3_temp->info['replay_gain'];
                    }
                    unset($getid3_temp, $getid3_apetag);
                }
            }
        }

        return true;
    }

    /**
     * @param  type    $endoffset
     * @param  type    $version
     * @param  type    $length
     *
     * @return bool
     *
     * @link http://www.volweb.cz/str/tags.htm
     */
    public function getLyrics3Data($endoffset, $version, $length)
    {
        $info = &$this->getid3->info;

        if (!Helper::intValueSupported($endoffset)) {
            $info['warning'][] = 'Unable to check for Lyrics3 because file is larger than '.round(PHP_INT_MAX / 1073741824).'GB';

            return false;
        }

        fseek($this->getid3->fp, $endoffset, SEEK_SET);
        if ($length <= 0) {
            return false;
        }
        $rawdata = fread($this->getid3->fp, $length);

        $ParsedLyrics3['raw']['lyrics3version'] = $version;
        $ParsedLyrics3['raw']['lyrics3tagsize'] = $length;
        $ParsedLyrics3['tag_offset_start'] = $endoffset;
        $ParsedLyrics3['tag_offset_end'] = $endoffset + $length - 1;

        if (substr($rawdata, 0, 11) != 'LYRICSBEGIN') {
            if (strpos($rawdata, 'LYRICSBEGIN') !== false) {
                $info['warning'][] = '"LYRICSBEGIN" expected at '.$endoffset.' but actually found at '.($endoffset + strpos($rawdata, 'LYRICSBEGIN')).' - this is invalid for Lyrics3 v'.$version;
                $info['avdataend'] = $endoffset + strpos($rawdata, 'LYRICSBEGIN');
                $rawdata = substr($rawdata, strpos($rawdata, 'LYRICSBEGIN'));
                $length = strlen($rawdata);
                $ParsedLyrics3['tag_offset_start'] = $info['avdataend'];
                $ParsedLyrics3['raw']['lyrics3tagsize'] = $length;
            } else {
                $info['error'][] = '"LYRICSBEGIN" expected at '.$endoffset.' but found "'.substr($rawdata, 0, 11).'" instead';

                return false;
            }
        }

        switch ($version) {

            case 1:
                if (substr($rawdata, strlen($rawdata) - 9, 9) == 'LYRICSEND') {
                    $ParsedLyrics3['raw']['LYR'] = trim(substr($rawdata, 11, strlen($rawdata) - 11 - 9));
                    $this->Lyrics3LyricsTimestampParse($ParsedLyrics3);
                } else {
                    $info['error'][] = '"LYRICSEND" expected at '.(ftell($this->getid3->fp) - 11 + $length - 9).' but found "'.substr($rawdata, strlen($rawdata) - 9, 9).'" instead';

                    return false;
                }
                break;

            case 2:
                if (substr($rawdata, strlen($rawdata) - 9, 9) == 'LYRICS200') {
                    $ParsedLyrics3['raw']['unparsed'] = substr($rawdata, 11, strlen($rawdata) - 11 - 9 - 6); // LYRICSBEGIN + LYRICS200 + LSZ
                    $rawdata = $ParsedLyrics3['raw']['unparsed'];
                    while (strlen($rawdata) > 0) {
                        $fieldname = substr($rawdata, 0, 3);
                        $fieldsize = (int) substr($rawdata, 3, 5);
                        $ParsedLyrics3['raw'][$fieldname] = substr($rawdata, 8, $fieldsize);
                        $rawdata = substr($rawdata, 3 + 5 + $fieldsize);
                    }

                    if (isset($ParsedLyrics3['raw']['IND'])) {
                        $i = 0;
                        $flagnames = array('lyrics', 'timestamps', 'inhibitrandom');
                        foreach ($flagnames as $flagname) {
                            if (strlen($ParsedLyrics3['raw']['IND']) > $i++) {
                                $ParsedLyrics3['flags'][$flagname] = $this->IntString2Bool(substr($ParsedLyrics3['raw']['IND'], $i, 1 - 1));
                            }
                        }
                    }

                    $fieldnametranslation = array('ETT' => 'title', 'EAR' => 'artist', 'EAL' => 'album', 'INF' => 'comment', 'AUT' => 'author');
                    foreach ($fieldnametranslation as $key => $value) {
                        if (isset($ParsedLyrics3['raw'][$key])) {
                            $ParsedLyrics3['comments'][$value][] = trim($ParsedLyrics3['raw'][$key]);
                        }
                    }

                    if (isset($ParsedLyrics3['raw']['IMG'])) {
                        $imagestrings = explode("\r\n", $ParsedLyrics3['raw']['IMG']);
                        foreach ($imagestrings as $key => $imagestring) {
                            if (strpos($imagestring, '||') !== false) {
                                $imagearray = explode('||', $imagestring);
                                $ParsedLyrics3['images'][$key]['filename'] = (isset($imagearray[0]) ? $imagearray[0] : '');
                                $ParsedLyrics3['images'][$key]['description'] = (isset($imagearray[1]) ? $imagearray[1] : '');
                                $ParsedLyrics3['images'][$key]['timestamp'] = $this->Lyrics3Timestamp2Seconds(isset($imagearray[2]) ? $imagearray[2] : '');
                            }
                        }
                    }
                    if (isset($ParsedLyrics3['raw']['LYR'])) {
                        $this->Lyrics3LyricsTimestampParse($ParsedLyrics3);
                    }
                } else {
                    $info['error'][] = '"LYRICS200" expected at '.(ftell($this->getid3->fp) - 11 + $length - 9).' but found "'.substr($rawdata, strlen($rawdata) - 9, 9).'" instead';

                    return false;
                }
                break;

            default:
                $info['error'][] = 'Cannot process Lyrics3 version '.$version.' (only v1 and v2)';

                return false;
                break;
        }

        if (isset($info['id3v1']['tag_offset_start']) && ($info['id3v1']['tag_offset_start'] <= $ParsedLyrics3['tag_offset_end'])) {
            $info['warning'][] = 'ID3v1 tag information ignored since it appears to be a false synch in Lyrics3 tag data';
            unset($info['id3v1']);
            foreach ($info['warning'] as $key => $value) {
                if ($value == 'Some ID3v1 fields do not use NULL characters for padding') {
                    unset($info['warning'][$key]);
                    sort($info['warning']);
                    break;
                }
            }
        }

        $info['lyrics3'] = $ParsedLyrics3;

        return true;
    }

    /**
     * @param  type    $rawtimestamp
     *
     * @return bool
     */
    public function Lyrics3Timestamp2Seconds($rawtimestamp)
    {
        if (preg_match('#^\\[([0-9]{2}):([0-9]{2})\\]$#', $rawtimestamp, $regs)) {
            return (int) (($regs[1] * 60) + $regs[2]);
        }

        return false;
    }

    /**
     * @param  type    $Lyrics3data
     *
     * @return bool
     */
    public function Lyrics3LyricsTimestampParse(&$Lyrics3data)
    {
        $lyricsarray = explode("\r\n", $Lyrics3data['raw']['LYR']);
        foreach ($lyricsarray as $key => $lyricline) {
            $regs = array();
            unset($thislinetimestamps);
            while (preg_match('#^(\\[[0-9]{2}:[0-9]{2}\\])#', $lyricline, $regs)) {
                $thislinetimestamps[] = $this->Lyrics3Timestamp2Seconds($regs[0]);
                $lyricline = str_replace($regs[0], '', $lyricline);
            }
            $notimestamplyricsarray[$key] = $lyricline;
            if (isset($thislinetimestamps) && is_array($thislinetimestamps)) {
                sort($thislinetimestamps);
                foreach ($thislinetimestamps as $timestampkey => $timestamp) {
                    if (isset($Lyrics3data['synchedlyrics'][$timestamp])) {
                        // timestamps only have a 1-second resolution, it's possible that multiple lines
                        // could have the same timestamp, if so, append
                        $Lyrics3data['synchedlyrics'][$timestamp] .= "\r\n".$lyricline;
                    } else {
                        $Lyrics3data['synchedlyrics'][$timestamp] = $lyricline;
                    }
                }
            }
        }
        $Lyrics3data['unsynchedlyrics'] = implode("\r\n", $notimestamplyricsarray);
        if (isset($Lyrics3data['synchedlyrics']) && is_array($Lyrics3data['synchedlyrics'])) {
            ksort($Lyrics3data['synchedlyrics']);
        }

        return true;
    }

    /**
     * @param  type         $char
     *
     * @return bool|null
     */
    public function IntString2Bool($char)
    {
        if ($char == '1') {
            return true;
        } elseif ($char == '0') {
            return false;
        }

        return;
    }
}
